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The Use Of Tilt Angle In Gravity And Magnetic Methods, Uğur Akin, Betül Işikdeni̇z Şeri̇foğlu, Mehmet Duru
The Use Of Tilt Angle In Gravity And Magnetic Methods, Uğur Akin, Betül Işikdeni̇z Şeri̇foğlu, Mehmet Duru
Bulletin of the Mineral Research and Exploration
Tilt angle method, which has been recently used in investigating the boundaries of structures, reveals useful information on deep and shallow structures. Tilt angle is expressed as the arctan value of the ratio of the vertical derivative of the potential field to its horizontal derivative. The method was applied to Kýrþehir-Ý31 Sheet. As a result, the presence of volcanites buried under terrestrial sediments was demonstrated.
Fiber Metamaterials With Negative Magnetic Permeability In The Terahertz, Anna Wang, Alessandro Tuniz, Peter Hunt, Elise Pogson, R A. Lewis, Avi Bendavid, Simon Fleming, Boris Kuhlmey, Maryanne Large
Fiber Metamaterials With Negative Magnetic Permeability In The Terahertz, Anna Wang, Alessandro Tuniz, Peter Hunt, Elise Pogson, R A. Lewis, Avi Bendavid, Simon Fleming, Boris Kuhlmey, Maryanne Large
Roger A. Lewis
We present a novel method for producing metamaterials with a terahertz magnetic response via fiber drawing, which can be inexpensively scaled up to mass production. We draw a centimeter preform to fiber, spool it, and partially sputter it with metal to produce extended slotted resonators. We characterize metamaterial fiber arrays with different orientations via terahertz time domain spectroscopy, observing distinct magnetic resonances between 0.3 and 0.4 THz, in excellent agreement with simulations. Numerical parameters retrieval techniques confirm that such metamaterials possess negative magnetic permeability. Combined with fiber-based negative permittivity materials, this will enable the development of the first woven negative …
Magneto-Radiotherapy: Effect Of Magnetic Field On Dose Distribution And Rbe, Heidi Nettelbeck, Anatoly B. Rosenfeld, George J. Takacs, Michael L. Lerch
Magneto-Radiotherapy: Effect Of Magnetic Field On Dose Distribution And Rbe, Heidi Nettelbeck, Anatoly B. Rosenfeld, George J. Takacs, Michael L. Lerch
George Takacs
Magneto-radiotherapy is the application of magnetic fields during radiotherapy procedures. It aims to improve the quality of cancer treatment by altering the dose deposition of charged particles in the tissue volume being targeted. Our research has focused on applying the concept of magneto-radiotherapy to conventional linac treatment and MRT (Microbeam Radiation Therapy) oncology modalities.
Effect Of Transverse Magnetic Fields On Dose Distribution And Rbe Of Photon Beams: Comparing Penelope And Egs4 Monte Carlo Codes, Heidi Nettelbeck, George Takacs, Anatoly Rosenfeld
Effect Of Transverse Magnetic Fields On Dose Distribution And Rbe Of Photon Beams: Comparing Penelope And Egs4 Monte Carlo Codes, Heidi Nettelbeck, George Takacs, Anatoly Rosenfeld
George Takacs
The application of a strong transverse magnetic field to a volume undergoing irradiation by a photon beam can produce localized regions of dose enhancement and dose reduction. This study uses the PENELOPE Monte Carlo code to investigate the effect of a slice of uniform transverse magnetic field on a photon beam using different magnetic field strengths and photon beam energies. The maximum and minimum dose yields obtained in the regions of dose enhancement and dose reduction are compared to those obtained with the EGS4 Monte Carlo code in a study by Li et al (2001), who investigated the effect of …
Highly Efficient Extraction Of Phenolic Compounds By Use Of Magnetic Room Temperature Ionic Liquids For Environmental Remediation, Ning Deng, Min Li, Lijie Zhao, Chengfei Lu, Sergio L. De Rooy, Isiah M. Warner
Highly Efficient Extraction Of Phenolic Compounds By Use Of Magnetic Room Temperature Ionic Liquids For Environmental Remediation, Ning Deng, Min Li, Lijie Zhao, Chengfei Lu, Sergio L. De Rooy, Isiah M. Warner
Faculty Publications
A hydrophobic magnetic room temperature ionic liquid (MRTIL), trihexyltetradecylphosphonium tetrachloroferrate(III) ([3C 6PC 14][FeCl 4]), was synthesized from trihexyltetradecylphosphonium chloride and FeCl 3·6H 2O. This MRTIL was investigated as a possible separation agent for solvent extraction of phenolic compounds from aqueous solution. Due to its strong paramagnetism, [3C 6PC 14][FeCl 4] responds to an external neodymium magnet, which was employed in the design of a novel magnetic extraction technique. The conditions for extraction, including extraction time, volume ratio between MRTIL and aqueous phase, pH of aqueous solution, and structures of phenolic compounds were investigated and optimized. The magnetic extraction of phenols …
Time Optimal Control In Spin Systems, Navin Khaneja, Roger Brockett, Steffen J. Glaser
Time Optimal Control In Spin Systems, Navin Khaneja, Roger Brockett, Steffen J. Glaser
Dartmouth Scholarship
In this paper, we study the design of pulse sequences for nuclear magnetic resonance spectroscopy as a problem of time optimal control of the unitary propagator. Radio-frequency pulses are used in coherent spectroscopy to implement a unitary transfer between states. Pulse sequences that accomplish a desired transfer should be as short as possible in order to minimize the effects of relaxation and to optimize the sensitivity of the experiments. Here, we give an analytical characterization of such time optimal pulse sequences applicable to coherence transfer experiments in multiple-spin systems. We have adopted a general mathematical formulation, and present many of …
Experimental Investigation Of The Vibration Characteristics Of A Magnetorheological Elastomer Sandwich Beam Under Non-Homogeneous Small Magnetic Fields, Guoliang Hu, Miao Guo, Weihua Li, Haiping Du, Gursel Alici
Experimental Investigation Of The Vibration Characteristics Of A Magnetorheological Elastomer Sandwich Beam Under Non-Homogeneous Small Magnetic Fields, Guoliang Hu, Miao Guo, Weihua Li, Haiping Du, Gursel Alici
Faculty of Informatics - Papers (Archive)
In this study, a magnetorheological elastomer (MRE) was manufactured and tested, and a MRE sandwich beam was also fabricated from a MRE between two thin aluminum layers. An experimental test rig was set up to investigate the vibration response of the MRE sandwich beam under a non-homogeneous magnetic field. The experimental results show that the first natural frequency of the MRE sandwich beam decreased as the magnetic field applied to the beam was moved from the clamped end of the beam to the free end of the beam. It is also noted that the MRE sandwich beam had the capability …
Magnetic Properties In Polycrystalline And Single Crystal Ca-Doped Lacoo3, R Zeng, J C. Debnath, Dapeng Chen, P Shamba, Jianli Wang, S J. Kennedy, S J. Campbell, Tania M. Silver, S. X. Dou
Magnetic Properties In Polycrystalline And Single Crystal Ca-Doped Lacoo3, R Zeng, J C. Debnath, Dapeng Chen, P Shamba, Jianli Wang, S J. Kennedy, S J. Campbell, Tania M. Silver, S. X. Dou
Faculty of Engineering - Papers (Archive)
Polycrystalline (PC) and single crystalline (SC) Ca-doped LaCoO3 (LCCO) samples with the perovskite structure were synthesized by conventional solid-state reaction and the floating-zone growth method. We present the results of a comprehensive investigation of the magnetic properties of the LCCO system. Systematic measurements have been conducted on dc magnetization, ac susceptibility, exchange-bias, and the magnetocaloric effect. These findings suggest that complex structural phases, ferromagnetic (FM), and spin-glass/cluster-spin-glass (CSG), and their transitions exist in PC samples, while there is a much simpler magnetic phase in SC samples. It was also of interest to discover that the CSG induced a magnetic …
Fabrication, Magnetic, And Ferroelectric Properties Of Multiferroic Bifeo3 Hollow Nanoparticles, Yi Du, Zhenxiang Cheng, S X. Dou, Darren J. Attard, Xiaolin Wang
Fabrication, Magnetic, And Ferroelectric Properties Of Multiferroic Bifeo3 Hollow Nanoparticles, Yi Du, Zhenxiang Cheng, S X. Dou, Darren J. Attard, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
Hollow BiFeO3 nanoparticles were synthesized by an electrospray route for the first time. The phase purity and structure have been investigated by x-ray diffraction and Raman spectroscopy. Transmission and scanning electron microscope investigations revealed that the as-obtained BiFeO3 hollow spheres were polycrystalline, with a shell thickness of 35 nm. The formation mechanism can be possibly explained by Ostwald ripening. Raman spectra have verified decreased vibrational frequencies in BiFeO3 nanoparticles. These hollow and core-shell multiferroic nanoparticles exhibit significantly enhanced ferromagnetism from 5 to 600 K due to a broken spiral spin structure. The ferroelectricity of hollow BiFeO3 …
Magnetoresistance, Critical Current Density, And Magnetic Flux Pinning Mechanism In Nickel Doped Bafe2as2 Single Crystals, Mahboobeh Shahbazi, Xiaolin Wang, Z W. Lin, J G. Zhu, S. X. Dou, K Y. Choi
Magnetoresistance, Critical Current Density, And Magnetic Flux Pinning Mechanism In Nickel Doped Bafe2as2 Single Crystals, Mahboobeh Shahbazi, Xiaolin Wang, Z W. Lin, J G. Zhu, S. X. Dou, K Y. Choi
Faculty of Engineering - Papers (Archive)
The critical current density, Jc, flux pinning behavior and magneto- resistance results of BaFe2-xNixAs2 single crystal have been investigated in fields up to 13 T over a temperature range of 2 to 20 K. The magnetoresistance below the superconducting transition temperature (Tc) shows Arrhenius thermally activated behavior: ρ = ρoexp(-Uo(T,H)/kBT), where Uo is the thermally activated energy. BaFe2-xNixAs2 exhibits high thermally activated flux flow energy with a very weak …
Reduction Of Hysteresis Losses In The Magnetic Refrigerant La0.8ce0.2fe11.4si1.6 By The Addition Of Boron, Precious Shamba, J.C Debnath, Rong Zeng, Jianli Wang, Stewart J. Campbell, S J. Kennedy, S. X. Dou
Reduction Of Hysteresis Losses In The Magnetic Refrigerant La0.8ce0.2fe11.4si1.6 By The Addition Of Boron, Precious Shamba, J.C Debnath, Rong Zeng, Jianli Wang, Stewart J. Campbell, S J. Kennedy, S. X. Dou
Faculty of Engineering - Papers (Archive)
In an effort to improve the magnetocaloric effects of the NaZn13-type La0.8Ce0.2Fe11.4Si1.6 compound, the effect of boron doping on the magnetic properties and magnetocaloric properties has been investigated. The magnetic entropy change (ΔSM) for the La0.8Ce0.2Fe11.4Si1.6 compound, obtained for a field change of 0–5 T using the Maxwell relation exhibits a spike and appears to be overestimated and is thus corrected by using the Clausius-Clapeyron equation (CC). The ΔSM determined from the CC equation is estimated to be 19.6 J kg …
Magnetic And Ferroelectric Properties Of Multiferroic Bi2nimno6 Nanoparticles, Yi Du, Zhenxiang Cheng, Xiaolin Wang, Peng Liu, S. X. Dou
Magnetic And Ferroelectric Properties Of Multiferroic Bi2nimno6 Nanoparticles, Yi Du, Zhenxiang Cheng, Xiaolin Wang, Peng Liu, S. X. Dou
Faculty of Engineering - Papers (Archive)
Multiferroic Bi2NiMnO6 nanoparticles were synthesized by a simple electrospray method. Bi2NiMnO6 nanoparticles crystallize in the monoclinic structure with space group C121. The particles show a uniform spherical shape with a diameter of 100 nm to 300 nm. The ferromagnetic transition of Bi2NiMnO6 is confirmed at 122 K. The room temperature ferroelectricity of the Bi2NiMnO6 nanoparticles is verified by Kelvin probe force microscopy.
Continuously Tunable Magnetic Phase Transitions In The Dymn1-Xfexo3 System, Fang Hong, Zhenxiang Cheng, Hongyang Zhao, Hideo Kimura, Xiaolin Wang
Continuously Tunable Magnetic Phase Transitions In The Dymn1-Xfexo3 System, Fang Hong, Zhenxiang Cheng, Hongyang Zhao, Hideo Kimura, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
The structure and magnetic properties of perovskite DyMn1−xFexO3 samples have been studied. Static orbital orderings are expected to exist in samples with x ≤ 0.2 due to strong Jahn-Teller distortion, which become less stable as x increases and probably disappears in samples with x > 0.5. The antiferromagnetic transition temperature increases as x increases. At the composition x > 0.5, spin reorientation starts to appear. Meanwhile, the spin reorientation temperature and the antiferromagnetic Néel temperature gradually separate and widen the temperature range of the magnetic metastable state between these two transitions. The magnetic competition is discussed based …
Giant Magnetic Flux Jumps In Single Crystals Of Ba0.6k0.4fe2as2, Ki-Young Choi, Gun Sang Jeon, X.F Wang, X.H Chen, Xiaolin Wang, Myung-Hwa Jung, Sung-Ik Lee, Gangseo Park
Giant Magnetic Flux Jumps In Single Crystals Of Ba0.6k0.4fe2as2, Ki-Young Choi, Gun Sang Jeon, X.F Wang, X.H Chen, Xiaolin Wang, Myung-Hwa Jung, Sung-Ik Lee, Gangseo Park
Faculty of Engineering - Papers (Archive)
Giant magnetic flux jumps are observed in magnetic hysteresis loops of Ba0.6K0.4Fe2As2 single crystals. The size of the flux jumps, which appear only at low temperatures (T<4 >K), is so large that it can transform the whole superconducting state into the normal state. The recovery rate to the superconducting state is rather slow, although the superconducting state is almost fully recovered. We show that theoretical predictions based on the adiabatic approach with nonlocal electrodynamics give a good explanation of the flux jumps observed in the single crystals of Ba0.6K0.4 …
Neutron Diffraction Study Of The Magnetic Order In Ndmn2ge1.6si0.4, Jianli Wang, Stewart J. Campbell, John M. Cadogan, A J Studer, Rong Zeng, S. X. Dou
Neutron Diffraction Study Of The Magnetic Order In Ndmn2ge1.6si0.4, Jianli Wang, Stewart J. Campbell, John M. Cadogan, A J Studer, Rong Zeng, S. X. Dou
Faculty of Engineering - Papers (Archive)
Here we report a detailed investigation of NdMn2Ge1.6Si0.4; this forms part of our investigation of the magnetic order across the NdMn2Ge2−xSix (x = 0–2.0) series by magnetometry, x-ray diffraction and neutron diffraction over the temperature range 6–465 K. On decreasing the temperature from 465 K, NdMn2Ge1.6Si0.4 exhibits four magnetic transitions: (i) from paramagnetism to intralayer antiferromagnetism AFl at TIntraN ~ 430 K; (ii) AFl to canted ferromagnetism Fmc at TInterC ~ 330 K; (iii) Fmc to conical magnetic ordering …
Magnetic And Structural Properties Of Zinc-Doped Nickel Ferrite, Kanokporn Chattrakun
Magnetic And Structural Properties Of Zinc-Doped Nickel Ferrite, Kanokporn Chattrakun
Open Access Theses & Dissertations
We have used dc-magnetization, ac-magnetic susceptibility and x-ray diffraction (XRD) to investigate the microscopic origin of the magnetic property modifications induced by zinc doping in bulk and nano-sized nickel ferrite. Magnetic measurements indicate that the nanoparticle energy barrier to magnetization reversal, EB, and the bulk saturation magnetization, Ms, follow similar dependences on the zinc doping fraction, x. Both these magnetic quantities initially increase with increasing x, reach a maximum at x~0.5, and eventually decrease upon further doping. Synchrotron and laboratory powder XRD data show no evidence of significant structural modifications for x~0.5: we find the lattice …
Fiber Metamaterials With Negative Magnetic Permeability In The Terahertz, Anna Wang, Alessandro Tuniz, Peter Hunt, Elise Pogson, R A. Lewis, Avi Bendavid, Simon Fleming, Boris Kuhlmey, Maryanne Large
Fiber Metamaterials With Negative Magnetic Permeability In The Terahertz, Anna Wang, Alessandro Tuniz, Peter Hunt, Elise Pogson, R A. Lewis, Avi Bendavid, Simon Fleming, Boris Kuhlmey, Maryanne Large
Faculty of Engineering - Papers (Archive)
We present a novel method for producing metamaterials with a terahertz magnetic response via fiber drawing, which can be inexpensively scaled up to mass production. We draw a centimeter preform to fiber, spool it, and partially sputter it with metal to produce extended slotted resonators. We characterize metamaterial fiber arrays with different orientations via terahertz time domain spectroscopy, observing distinct magnetic resonances between 0.3 and 0.4 THz, in excellent agreement with simulations. Numerical parameters retrieval techniques confirm that such metamaterials possess negative magnetic permeability. Combined with fiber-based negative permittivity materials, this will enable the development of the first woven negative …
Effects Of Cu And Fe Doping On Raman Spectra And On The Structural And Magnetic Properties Of Ermno3, Peng Liu, Zhenxiang Cheng, Yi Du, Xiaolin Wang
Effects Of Cu And Fe Doping On Raman Spectra And On The Structural And Magnetic Properties Of Ermno3, Peng Liu, Zhenxiang Cheng, Yi Du, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
Single phase ErMexMn1−xO3 (Me = Cu, Fe; 0 ≤ x ≤ 0.1) samples were synthesized by the solid state reaction method. The differences between the doping effects on the Raman spectra and on the structural, magnetic, and thermal properties of the two systems have been systematically investigated. In the ErCuxMn1−xO3 system, lattice parameter a increases with doping, while lattice parameter c decreases. It is more complicated in the ErFexMn1−xO3 system, where lattice parameter a decreases with doping, while lattice parameter c is enhanced after an …
Magnetic Phase Transition And Mossbauer Spectroscopy Of Erni2mnx Compounds, Jianli Wang, S J. Campbell, R Zeng, S. X. Dou, S J. Kennedy
Magnetic Phase Transition And Mossbauer Spectroscopy Of Erni2mnx Compounds, Jianli Wang, S J. Campbell, R Zeng, S. X. Dou, S J. Kennedy
Faculty of Engineering - Papers (Archive)
Investigation of ErNi2Mnx with 0.90 ≤ x ≤ 1.10 indicates that the MgCu2-type structure (with space group Fd-3m) is formed within x = 0.97−1.10. Curie temperature TC = 50 K of ErNi2Mn is significantly higher than those of the corresponding ErNi2 (TC = 7 K) and ErMn2 (TC = 15 K) compounds. Detailed analyses of DC magnetization data demonstrate that the magnetic phase transition at the Curie temperature is second order. The magnetic entropy change around TC has been found to be 4.8 J/kg K for …
Magnetic Properties Of The Bishop Ash In The San Andreas Fault Borderlands, Becky Strauss
Magnetic Properties Of The Bishop Ash In The San Andreas Fault Borderlands, Becky Strauss
Honors Papers
The San Andreas Fault marks one of the most tectonically active regions of the United States, producing frequent earthquakes that have decimated major population centers throughout central and southern California. Its northern regions have been thoroughly studied, but the complex behavior of the southeast portion of the fault is often neglected, in spite of its potential to nucleate a major earthquake within the next few centuries. In this study, I examined the magnetic traits of the Bishop Ash, a well-dated marker horizon of volcanic ash, to assess deformation adjacent to this part of the fault at hand-sample scale. To this …
Robust High-Temperature Magnetic Pinning Induced By Proximity In Yba2cu3o7-8/La0.67sr0.33mno3 Hybrids, C.Z Chen, Z Y. Liu, Y M. Lu, L Zeng, C B. Cai, Rong Zeng, S. X. Dou
Robust High-Temperature Magnetic Pinning Induced By Proximity In Yba2cu3o7-8/La0.67sr0.33mno3 Hybrids, C.Z Chen, Z Y. Liu, Y M. Lu, L Zeng, C B. Cai, Rong Zeng, S. X. Dou
Faculty of Engineering - Papers (Archive)
An elaborately designed bilayer consisting of superconducting YBa2Cu3O7-6 (YBCO) and ferromagnetic La0.67Sr0.33MnO3-6 (LSMO) was prepared on a single crystal LaAlO3 substrate by pulsed laser deposition (PLD), with a view to understanding the mechanism behind the influence of superconductor/ferromagnet proximity on the critical current density, Jc. The present bilayer system shows significant modifications in Jc, as evidenced by the suppressed decay of its temperature dependence, as well as the crossing behavior of the magnetic field dependence of Jc at high temperatures. This indicates that enhanced …
Critical Magnetic Transition In Tbni2mn-Magnetization And Mossbauer Spectroscopy, Jianli Wang, S J. Campbell, S J. Kennedy, Rong Zeng, S. X. Dou, Guangheng Wu
Critical Magnetic Transition In Tbni2mn-Magnetization And Mossbauer Spectroscopy, Jianli Wang, S J. Campbell, S J. Kennedy, Rong Zeng, S. X. Dou, Guangheng Wu
Faculty of Engineering - Papers (Archive)
The structural and magnetic properties of the TbNi2Mnx series (0.9 ≤ x ≤ 1.10) have been investigated using x-ray diffraction, field- and temperature-dependent ac magnetic susceptibility,DC magnetization (5-340 K; 0-5 T) and 57Fe Mössbauer spectroscopy (5-300 K). TbNi2Mnx crystallize in the MgCu2-type structure (space group Fd-3m). The additional contributions to the magnetic energy terms from transition metal-transition metal interactions (T-T) and rare earthtransition metal interactions (R-T) in RNi2Mn contribute to their increased magnetic ordering temperatures compared with RNi2 and RMn2. Both the lattice constant a and the Curie temperature TC exhibit maximal values at the x=1 composition indicating strong magnetostructural …
The Effects Of Size And Orientation On Magnetic Properties And Exchange Bias In Co3o4 Mesoporous Nanowires, Rong Zeng, J Q Wang, Zhixin Chen, Wenxian Li, S. X. Dou
The Effects Of Size And Orientation On Magnetic Properties And Exchange Bias In Co3o4 Mesoporous Nanowires, Rong Zeng, J Q Wang, Zhixin Chen, Wenxian Li, S. X. Dou
Faculty of Engineering - Papers (Archive)
Co3O4 mesoporous nanowires with average single crystalline grain sizes of about 8 nm, 12nm, 25 nm, and 45 nm were synthesized by sintering of microwave-assisted hydrothermal processed belt-Co(OH)2 precursors at 300–500 °C for 2 h. Microstructure analysis was conducted by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), field emission SEM (FESEM), transmission electron microscopy (TEM), and high resolution TEM (HRTEM) to confirm the composition, structure, and orientation in the nanowires. Systematic magnetic measurements have also been conducted on the nanowires. It was found that the size and orientation have significant effects on …
Strong 4f Electron Interaction And Magnetic Ordering Modification In Nd1-Xerxmno3 (0 Less Than Or Equal To X Less Than Or Equal To 0.5), Fang Hong, Zhenxiang Cheng, Xiaolin Wang
Strong 4f Electron Interaction And Magnetic Ordering Modification In Nd1-Xerxmno3 (0 Less Than Or Equal To X Less Than Or Equal To 0.5), Fang Hong, Zhenxiang Cheng, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
Structural and magnetic properties have been studied in perovskite Nd1-xErxMnO3 (0 ≤ x ≤ 0.5). Er3+ doping enhances the Jahn-Teller distortion, strongly affects the Nd3+-Mn3+ interaction, destroys the intermediate state below the antiferromagnetic transition temperature in NdMnO3, and breaks the antiparallel arrangement between Nd3+ and Mn3+ spin ordering. The decreasing ferromagnetic component in magnetic hysteresis loops at 30 K indicates that the canted angles vary with x. These results offer strong evidence for the interaction between rare earth ions and transition metal ions and competition among rare …
Novel Magnetocaloric Materials And Room Temperature Magnetic Refrigeration, Jyotish Chandra Debnath
Novel Magnetocaloric Materials And Room Temperature Magnetic Refrigeration, Jyotish Chandra Debnath
University of Wollongong Thesis Collection 1954-2016
Modern society relies on cooling technology for food safety, comfort and medical applications. For example, in the US about 34% of the electricity is consumed by cooling appliances and 15% of the total worldwide energy consumption involves the use of refrigeration (air conditioning, refrigeration, freezing, chilling, etc.). Nowadays, most cooling devices are based on vapour-compression technology, which uses strong greenhouse gases and the energy efficiency has reached its limit, the increased international concerns over global warming due to ever increasing energy consumption calls for a change. Currently, several solid-sate cooling technologies, such as optical refrigeration, thermoelectric refrigeration, electric refrigeration, and …
Early Magnetic B-Type Stars: X-Ray Emission And Wind Properties, Lidia Oskinova, Helge Todt, Richard Ignace, John Brown, Joseph Cassinelli, Wolf-Rainer Hamann
Early Magnetic B-Type Stars: X-Ray Emission And Wind Properties, Lidia Oskinova, Helge Todt, Richard Ignace, John Brown, Joseph Cassinelli, Wolf-Rainer Hamann
ETSU Faculty Works
We present a comprehensive study of X-ray emission and wind properties of magnetic early B-type stars. We compile the complete sample of early B-type stars with detected magnetic fields to date and existing X-ray measurements, in order to study whether the X-ray emission can be used as a general proxy for stellar magnetism. For the first time we analyze the UV spectra of B stars with magnetic fields by means of non-LTE iron-blanketed stellar atmosphere model that account for the X-rays at the intensity and temperatures observed. The mass-loss rates inferred from the analysis of UV lines are significantly lower …
Spin-Dependent Electron Transport In Nanomagnetic Thin Film Devices, Yun Zhou
Spin-Dependent Electron Transport In Nanomagnetic Thin Film Devices, Yun Zhou
School of Engineering, Computing and Mathematics Theses
Spin-dependent electron transport in submicron/nano sized magnetic thin film devices fabricated using the optical lithography, e-beam lithography and focused ion beam (FIB) was investigated with the primary aim to find the ballistic magnetoresistance (BMR) in thin film nanoconstrictions. All experimental results were analysed in combination with micromagnetic simulations. The magnetisation reversal processes were investigated in a submicron half-pinned NiFe stripe with a microconstriction. An asymmetric MR curve was observed, and micromagnetic simulations verified it was due to the exchange-bias on the left side, which changed the magnetic switching mechanism. The effects of different pinning sites on the magnetisation switching and …